A Reserch Of Algorithm For Non-probabilistic Reliability And Its Application In Girder Bridge

With the continuous development of reliability theory,the traditional reliability theory based on probability theory and mathematical statistical methods in the absence of randomized data has its limitations to deal with engineering problems.Small errors in data often lead to large error in reliability calculation.The accurate information of uncertain variables is difficult to obtain in practical engineering.Non-probabilistic reliability theory that describe uncertainty with a collection of models has a stronger applicability in engineering.Bridge project as part of the national infrastructure plays an irreplaceable role on Traffic Engineering.People pay more and more attention to its reliability.Girder bridge has good integrity,adaptability and durability,and it's widely used in existing bridges.The girder bridge built in the 1980 s needs repair or reinforcement with increasing traffic and time.Therefore,to assess the reliability of the girder bridge is necessary.The non-probabilistic reliability theory applied for existing girder bridge assessment has become a new research direction.This thesis describes the basic concepts of reliability,introduces basic nonprobabilistic reliability theory and computational methods.It studies non-probabi lity response surface method to improve and simplify,then make girder bridg es non-probabilistic reliability assessment calculation and analysis system that can be used to analyze the actual bridge engineering.The main contents of this thesis are the following:(1)Analyze and compare several common algorithm of non-probabilistic reli-ability index,study on a response surface method without limit state equation case,then propose an improved response surface method and simplified response surface method to reduce the computation quantity under the condition of ensur-ing the accuracy.(2)Introduce a assessment calculation and analysis system with non-probab-ilistic reliability on girder bridge.Introduce how to transform this method thro-ugh the Ansys,Matlab software into numerical calculation in detail.(3)Analysis of engineering example with the application of improved responsesurface method and the use the non-probabilistic reliability assessment method of girder bridge.Through the actual girder bridge non-probabilistic reliability assessment,the algorithm proved practical and evaluation system is practical.